Method of making sheet metal caps



Oct. 22, 1935. v E. H. JOHNSON 2,018,022,

METHOD OF MAKING SHEET M TAL CAPS Filed March 27, 1935 2 Sheets-Sheet 1 l r I 17 i4 2 I Oct. 22, 1935. E. H. JOHNSON 2,018,022 9 METHOD OF MAKING SHEET METAL CAPS Filed March 27, 1933 2 Sheets-Sheet 2 Patented Oct. 22, 1935 PATENT OFFICE METHOD OF MAKING sneer METAL oars Edward H. Johnson, Toledo, Ohio, assignor to 511:? Closure Service Company, a corporation of A t Application March 2'1, 1933, Serial No. 662,911, 2 Claims. (Cl. 113-121) My invention relates to a method of making caps of sheet material to be used as closures for bottles, jars or other containers.

An object of the invention is to provide a prac- 5 tical method -of making a cap with double walls from a single piece of sheet metal. More particularly the invention comprises a novel method of stamping a disk from a sheet of metal and shaping the cap from said disk by a series of drawing 10 operations performed in successive steps by means of dies.

Other objects of the invention and the exact nature thereof will appear more fully hereinafter;

In the accompanying drawings;

15 Fig. l is a diagrammatic view of a flat strip of sheet metal from which the blanks are stamped.

Fig. 2 is a sectional elevation of a cutter and dies by which a blank is stamped out and partially formed by a preliminary drawing operation 20 which draws the inner flange portion of the cap.

1 Fig. 3 is a fragmentary view of the dies shown in Fig. 2 at the completion of the first drawing operation, and before the dies have been separated. e

25 Fig. 4 is a sectional view of the blank as formed bythe'flrst drawing operation.

Fig. dis a view of the incomplete cap or blank shown in Fig. 4, but with the screw threads formed thereon. v p

30 Fig. 6 is a view showing a second set of dies for effecting an additional step in the drawing eration, andpermits the outer die Hi to continue operation.

Fig. 7 is a-"similar view with the dies brought together. I 30 Fig. 8 shows a pair of dies for effecting the final shaping operation.

Fig. 9 is a view of the same with the dies brought together. a

Fig. 10 is a sectional view of the completed cap. 40 Referring to Fig. 1, circular disks or blanks l2 are stamped from a flat strip l3 of sheet metal which is fed betweena pair of dies (Fig. 2). A stationary supporting platform or table I 4 has mounted thereon acutting ring l5 which coop- 45 erates with a cutter block or die l6 to sever the disk when said block is moved downward. Mounted on the platform I is a stationary lower die I! which cooperates w th an upper die l8 yieldingly mounted within the block) It for relative up and down movement. Between the lower die H and the ring I5. is a supporting ring l9 which is normally held withitsupper face in the same plane with the u perrate of the die n and ring Hi. The

ring I9 is carried on posts 20 which extend downward therefrom through openings in the platform 14 and are attached to a yoke or disk 2| beneath the platform. A post 22 secured to the platform 14 and extending downward therefrom provides a support for a. disk 23. A rubber block 24 mounted on the post 22 between the disks 2| and 23 provides a yielding support for the disk 2| and the ring I!) carried thereby.

In the operation of the dies shown in Fig. 2;

" after the sheet metal strip l3 has been fed forward into position between the dies,- the upper block I6 is moved downward and cooperates with the ring l5 to sever a circular blank or disk l2. As the block lfi continues its downward movement, the portion of the severed disk which extends beyond the top surface of the lower die I1, is carried downward and shaped between the lower die and the upper dies l6 and I8, as shown in Fig. 3, in which the upper dies have completed their downward movement. The upper die l8 in cooperation with the lower die l'l, draws a skirt or flange portion 25 downward from the top portion 26 of the blank. When the die l8 has completed its downward movement, the outer die block It continues to move downward, thereby drawing and shaping a vertical flange portion 2'l which 25 forms the lower part of the partially formed cap or blank. A coil spring 28 interposed between the inner and outer dies l8 and It, holds the inner die normally in its lowered position relative to the outer die I6, so that said dies move downward 30 together during the first part of the drawing opits downward movement after the die [8 has completed its downward movement. When the upper dies are lifted after the drawing operation, the rubber block 24 which has been compressed by the lowering of the platform l9 returns the platform to its normal position.

The next step in the formation of the blank shown in Fig. 4 consists in rolling threads 29 (Fig. 5) in the flange portion 25. The threaded blank is now ready for the second drawing operation which is performed by means of the dies shown in Figs. 6 and 7. "These include an annular die member 30 mounted on .a platform 3t. an inner die 32 yieldingly mounted for up and down movement in the die member 30, and an upper die 33. The upper portion of the die is of somewhat reduced diameter to receive the blank which seats thereon, while the lower flange portion 2? of the blank surrounds a reduced annular portion 34 of the die .30. The upper die 33 is of hollow cylindrical formation and is adapted to'surround the flange portion 5 91 the blank when moved downward. The die a carries a yielding head or plate a normally held in the lower end 01 the die by a coil spring has, When'the die a is moved downward, said headseatsontheblanhandasthediecon tinues its downward movement it is brought into position to surround the upper portion of the die-32 and thepartilottheblank. Aiurther downward movement of the upper die 33 carries the-die I2 downward therewith.- so that the die enters the part, N of the lower die 30, aszshown in Fig. 'l. The lower flange portionfl oi the blank is drawn upward by such movement of the dies to a vertical position between -die members 3! and 3|. llhe blank is thus given I the shape shown in Figs. '1 and 8 in which the outer portion 31 thereot-iorms the cylindrical,

outer wall 01' the cap.

Theflnalshaping oithecapiseflectedbythe v -diesshownin1"igs.8and9. Thesecomprise a lower die a and an upper die It. The die 39 is formed in its lower ialce with an annular recess ll by which the upper marginal portion 61 the flange 31 is-rolled inward and downward when the dies are brought together, thus tormingabeadli whichprovidesamarginaltop suriace'surroundlng the flat circular top 42 o! the cap. 9 shows the upper die II in its lowered position with the cap in its finished form and held between the dies. no. 10 shows the ca after it is removed from the dies.

Modifications may be resorted to within the spirit and scope of my invention.

What! claimis:

1; The method-01 0mm a cap from sheet material which comprises cutting a blank ,from a sheet of the material, drawing an intermediate portion of the blank downward substantially at right angles to a central circular portionottheblanktoiormaninnerwallor skirt portion depending from said central portion. drawing the outer circumierentialportion oi the blank upward into approximate parallelism 1o ,-with said inner skirt portion, and rolling the.

treeedgeormarginotsaidouter portioninwar d lyanddownwardlyintothespacebetweensaid inner and outer skirt portions and below the (:ir-

cula'r t9? P rtion. v

2. The method which comprises drawing an 1 intermediate portion .0! a sheetjmetal I "diskbetween diestoiorma circumferential flange portion extending substantially at right angles to a circular central portion o! thedisk, rollingzo screw-threads on said flange portion, bending the peripheral portion of the disk bacband drawing it into-an outer cylindrical flange'surrounding the screwthreadedinner-flangeportlon with "the free edge oitheouter-flange portion pro- 25 snwsnn a. Jonnson. 

